General Properties
Short Name:
Name:
POM (homo)
Polyoxymethylene (Homopolymer)
Polyoxymethylene, also designated POM-H, belongs to the classical engineering plastics. It has a large linear structure and is mostly produced from formaldehyde by means of polmyerization. POM as a homopolymer is mostly highly crystalline; the degree of Crystallinity / Degree of CrystallinityCrystallinity refers to the degree of structural order of a solid. In a crystal, the arrangement of atoms or molecules is consistent and repetitive. Many materials such as glass ceramics and some polymers can be prepared in such a way as to produce a mixture of crystalline and amorphous regions.crystallinity is typically between approx. 64% and 77%.
Structural Formula
Properties
NETZSCH Measurement
| Instrument | DSC 204 F1 Phoenix® |
| Sample Mass | 10.88 mg |
| IsothermalTests at controlled and constant temperature are called isothermal.Isothermal Phase | 7 min |
| Heating/Colling Rates | 10 K/min |
| Crucible | Al, pierced lid |
| Atmosphere | N2 (40 ml/min) |
Evaluation
The high degree of Crystallinity / Degree of CrystallinityCrystallinity refers to the degree of structural order of a solid. In a crystal, the arrangement of atoms or molecules is consistent and repetitive. Many materials such as glass ceramics and some polymers can be prepared in such a way as to produce a mixture of crystalline and amorphous regions.crystallinity of POM-H is reflected in the above DSC curve. It is dominated by a distinctive melting effect at 183°C (1st heating, blue, peak temperature) and 181°C (2nd heating, red, also peak temperature) as well as a quite small Glass Transition TemperatureThe glass transition is one of the most important properties of amorphous and semi-crystalline materials, e.g., inorganic glasses, amorphous metals, polymers, pharmaceuticals and food ingredients, etc., and describes the temperature region where the mechanical properties of the materials change from hard and brittle to more soft, deformable or rubbery.glass transition step at -77°C (midpoint). The height of the Glass Transition TemperatureThe glass transition is one of the most important properties of amorphous and semi-crystalline materials, e.g., inorganic glasses, amorphous metals, polymers, pharmaceuticals and food ingredients, etc., and describes the temperature region where the mechanical properties of the materials change from hard and brittle to more soft, deformable or rubbery.glass transition step Δcp is a measure for the amorphous content in the material while the melting enthalpy (here 195 J/g in the 2nd heating) is related to the crystalline content (in this case 62% – based on a theoretical enthalpy of a 100% crystalline material of 316 J/g); the larger the melting enthalpy, the larger the crystalline content. For semi-crystalline polymers, the magnitude of the Glass Transition TemperatureThe glass transition is one of the most important properties of amorphous and semi-crystalline materials, e.g., inorganic glasses, amorphous metals, polymers, pharmaceuticals and food ingredients, etc., and describes the temperature region where the mechanical properties of the materials change from hard and brittle to more soft, deformable or rubbery.glass transition and the height of the melting enthalpy are inversely proportional (i.e., if the heat of fusion increases, the Glass Transition TemperatureThe glass transition is one of the most important properties of amorphous and semi-crystalline materials, e.g., inorganic glasses, amorphous metals, polymers, pharmaceuticals and food ingredients, etc., and describes the temperature region where the mechanical properties of the materials change from hard and brittle to more soft, deformable or rubbery.glass transition step gets smaller and vice versa).